Reconfigurable robot systems provide several key potential advantages over traditional robots, including increased task versatility by adapting to better suit tasks, and reduced robot cost due to a smaller total number of modules, such as links and joints. As such, there has been significant research into the development of reconfigurable robots, with the most popular approach utilising modularity as the method of reconfiguration, as this allows for the interchangeability of parts, leading to self-repair [71, 60]. The reconfigurability feature has specifically been of interest in unstructured and unpredictable environments, characterised by changing operating contexts, which take the most advantage from robots that can adapt their shape and operating mode [66]. An alternative approach for the application of reconfigurable robot manipulators can be found in the industrial field of serial manipulators. In an ideal case, a manipulator would be designed with the exact number and configuration of joints necessary for its expected set of tasks [26].

Abstract--Through the implementation of reconfigurability to achieve flexibility and adaptation to tasks by morphology changes rather than by increasing the number of joints, malleable robots present advantages over traditional serial robot arms in regards to reduced weight, size, and cost. While limited in degrees of freedom (DOF), malleable robots still provide versatility across operations typically served by systems using higher DOF than required by the tasks. In this paper, we present the creation of a 2-DOF malleable robot, detailing the design of joints and malleable link, along with its modelling through forward and inverse kinematics, and a reconfiguration methodology that informs morphology changes based on end effector location-- determining how the user should reshape the robot to enable a task previously unattainable. The recalibration and motion planning for making robot motion possible after reconfiguration are also discussed, and thorough experiments with the prototype to evaluate accuracy and reliability of the system are presented. ECONFIGURABLE robot systems provide several key potential advantages over traditional robots, including of the robot (such as locomotion), albeit with a decrease in increased task versatility by adapting to better suit tasks, the performance for a specific task compared to a specialised and reduced robot cost due to a smaller total number of robot. While the majority of reconfigurable robots are modular, modules, such as links and joints. As such, there has been reconfiguration can also be achieved by locking aspects of significant research into the development of reconfigurable the robot. Examples include directly locking revolute joints to robots, with the most popular approach utilising modularity reduce the DOF of the robot [11], and locking passive cylindrical as the method of reconfiguration, as this allows for the joints carefully positioned to directly vary the Denavit-interchangeability of parts, leading to self-repair [1], [2].

Robotic arms built from stiffness-adjustable, continuously bending segments serially connected with revolute joints have the ability to change their mechanical architecture and workspace, thus allowing high flexibility and adaptation to different tasks with less than six degrees of freedom, a concept that we call malleable robots. Known stiffening mechanisms may be used to implement suitable links for these novel robotic manipulators; however, these solutions usually show a reduced performance when bending due to structural deformation. By including an inner support structure this deformation can be minimised, resulting in an increased stiffening performance. This paper presents a new multi-material spine-inspired flexible structure for providing support in stiffness-controllable layer-jamming-based robotic links of large diameter. The proposed spine mechanism is highly movable with type and range of motions that match those of a robotic link using solely layer jamming, whilst maintaining a hollow and light structure. The mechanics and design of the flexible spine are explored, and a prototype of a link utilising it is developed and compared with limb segments based on granular jamming and layer jamming without support structure. Results of experiments verify the advantages of the proposed design, demonstrating that it maintains a constant central diameter across bending angles and presents an improvement of more than 203% of resisting force at 180 degrees.